Of all the arguments against voluntary euthanasia, the most influential is the 'slippery slope': once we allow doctors to kill patients, we will not be able to limit the killing to those who want to die. Peter Singer
It's hard to get out of the barrel. It's slippery around the edges and people are happy to see you fall back in. Robert Downey, Jr.
There is nothing in the world that I loathe more than group activity, that communal bath where the hairy and slippery mix in a multiplication of mediocrity. Vladimir Nabokov
Torture is such a slippery slope; as soon as you allow a society or any legal system to do that, almost instantly you get a situation where people are being tortured for very trivial reasons. Iain Banks
I see women in their 30s getting plastic surgery, pulling this up and tucking that back. It's like a slippery slope - once you start you pull one thing one way and then you think, 'Oh my God, I've got to do the other side.' Halle Berry